Variable ratio throttle pedal

ABSTRACT

A pedal assembly includes a one-piece accelerator pedal without moving linkages that is mounted to a pin for rotational movement relative to a mounting stay. The throttle cable is operatively connected to the accelerator pedal for movement thereby as the pedal rotates, at least one of the pedal and mounting stay configured to provide a first ratio of pedal stroke movement relative to cable stroke movement at initial depression of the accelerator pedal, and a different, second ratio of pedal stroke movement relative to cable stroke movement upon further depression of the accelerator pedal.

BACKGROUND

The present disclosure relates to a throttle or accelerator pedal, andan associated method of developing more holding power resulting fromsimultaneously depressing a brake pedal and a throttle pedal bymodifying a ratio of the throttle pedal. It finds particular applicationin conjunction with a variable ratio throttle pedal. However, it is tobe appreciated that the present exemplary embodiment is also amenable toother like applications that encounter similar problems or requiresimilar solutions.

Currently, an accelerator pedal is pivotally moved relative to a mountor mounting stay. A throttle cable is, in turn, secured to theaccelerator pedal so that pulling of the throttle cable matches themovement of the accelerator pedal. That is, the cable stroke or cablepull ratio matches the ratio of pedal stroke movement throughout theactuation/deactuation of the pedal. There is only a small incidentalvariation in the ratio so that the cable pull ratio is dictated by theaccelerator pedal ratio. Typically, a line of action for the cable isaligned with a top of the accelerator pedal. The intent is to maintain alinear accelerator pedal input and as a result the cable end follows anarc controlled by a pivot location of the pedal. This ensures minimalchange to the pedal to cable stroke ratio.

It is desirable to assure that brake force builds faster than enginetorque when both brake and accelerator pedals are simultaneouslydepressed. Variable ratio throttle systems are per se known. The changein rate, however, is usually practical due to the environment the pedalsare subjected to. For example, water, ice, mud, etc. could potentiallylodge in the cam and as a result the throttle cable would becomedislodged from its desired line of action. Thus, a simplified structurethat assures that opening of an engine throttle is slower thanapplication of the brake is required. Also, with a variable ratio pedal,is desirable that the operator/driver not detect the slower action ofthe accelerator at small pedal angles and assure that action of theaccelerator at normal driving modes be in the range of traditional ormore normal pedal to cable pull ratios.

This disclosure remedies these problems in a simple, reliable,effective, and inexpensive manner.

BRIEF DESCRIPTION

There is provided a pedal assembly, namely an accelerator pedalassembly, in which a throttle cable attaches to an accelerator pedal atan angle so that the throttle cable provides a variable angle as thepedal is actuated or depressed, and wherein the pedal is a one-piecemember without moving linkages to provide the variable angle.

More particularly, the pedal assembly includes a mounting stay and a pinfixedly secured to the mounting stay. The one-piece accelerator pedalwithout moving linkages is mounted to the pin for rotational movementabout the pin relative to the mounting stay. The throttle cable isoperatively connected to the accelerator pedal for movement thereby asthe pedal rotates, at least one of the pedal and mounting stayconfigured to provide a first ratio of pedal stroke movement relative tocable stroke movement at initial depression of the accelerator pedal,and a different, second ratio of pedal stroke movement relative to cablestroke movement upon further depression of the accelerator pedal.

The throttle cable is secured to the accelerator pedal for initialmovement at an angle relative to a tangent of the pedal travel path.

The angle ranges from approximately 45° to approximately −7° relative tothe tangent of the pedal travel path.

The throttle cable is substantially tangent to the pedal travel path atthe end of the cable stroke.

The mounting stay includes a mounting region that receives the throttlecable and orients the throttle cable substantially perpendicular to aninitial portion of the angled pedal travel path.

The accelerator pedal includes a mounting region that receives a firstend of the throttle cable.

The pedal assembly further includes a brake pedal assembly that isconfigured to provide a brake force that is greater than an enginetorque.

The brake force is greater than the engine torque during the first ratioof pedal stroke movement relative to cable stroke movement at initialdepression of the accelerator pedal.

A method of varying a ratio of pedal stroke movement relative to cablestroke movement during actuation of an accelerator pedal includesmounting an accelerator pedal to a pin for rotational movement about thepin. The method further includes connecting a throttle cable to theaccelerator pedal for movement in different first and second ratios ofpedal stroke to cable stroke movement during actuation of theaccelerator pedal.

The method includes securing the throttle cable to the accelerator pedalfor initial movement at an angle relative to a tangent of the pedaltravel path.

The method includes providing a first ratio of pedal stroke movementrelative to cable stroke movement at initial depression of theaccelerator pedal, and a different, second ratio of pedal strokemovement relative to cable stroke movement upon further depression ofthe accelerator pedal.

The method includes providing a greater ratio of pedal stroke movementrelative to cable stroke movement during initial depression of theaccelerator pedal than later in the pedal stroke movement.

The method includes providing greater braking force than engine torqueduring the first ratio of pedal stroke movement relative to cable strokemovement at initial depression of the accelerator pedal.

The method includes forming the pedal as a one-piece component withoutmoving linkages.

One benefit of the present disclosure is assuring that the brake forcebuilds faster than the engine torque when both brake and acceleratorpedals are simultaneously depressed.

Yet another advantage is the ability to address this issue withoutsubstantially altering the remaining components of the current system.

Still another benefit is the simple, less complex manner of achieving avariable ratio throttle/accelerator pedal assembly.

Still other benefits and advantages will become apparent those skilledin the art after reading and understanding the following detaileddescription.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic elevational view of an accelerator pedal assemblyknown in the art.

FIG. 2 is an enlarged detail view of a portion of FIG. 1.

FIG. 3 is a representation of a line of action of a throttle cableassociated with the arrangement of FIGS. 1 and 2.

FIG. 4 is a graphical representation of pedal stroke versus cablestroke/pull.

FIG. 5 is a schematic elevational view of an accelerator pedal assemblyof the present disclosure.

FIG. 6 is a representation of a line of action of the throttle cableassociated with the accelerator pedal assembly of FIG. 5.

FIG. 7 is an enlarged detail view of a portion of FIG. 5.

FIG. 8 is a schematic elevational view of a mounting stay andaccelerator pedal.

FIG. 9 is an elevational view taken generally from along the right-handside of FIG. 8.

FIG. 10 is an enlarged cross-sectional view taken generally along thelines 10-10 of FIG. 8.

FIG. 11 is a schematic of a brake pedal assembly including a brakepedal.

DETAILED DESCRIPTION

The description and drawings herein are merely illustrative, and variousmodifications and changes can be made in the structures disclosedwithout departing from what is defined in the appended claims. Allreferences to direction and position, unless otherwise indicated, referto the orientation of the structures and components illustrated in thedrawings and should not be construed as limiting the claims appendedhereto. Like numbers refer to like parts throughout the several views.

With reference to FIG. 1, there is shown a pedal assembly 100 such asused in an associated vehicle (not shown). In this particular instance,the pedal assembly 100 is an accelerator pedal assembly which includesan accelerator pedal 110 having a first arm or portion 112 through whicha force is applied to the pedal, e.g. through application of a force viathe foot of the vehicle user, and a second arm or portion 114 thatconnects with an accelerator or throttle cable 120, particularly a firstend thereof. The pedal 110 is mounted for rotation on pin 124 that issecured to a mounting surface or mounting stay 130. The mounting stay130 is commonly secured to a firewall or panel (not shown) in a mannergenerally known in the art so that it is common for the mounting stay tobe secured to a substantially vertical wall of the vehicle. The pin 124is thus disposed in spaced relation relative to this vehicle wall andallows pivotal movement of the pedal 110.

Applying a force through the first arm 112 rotates the pedal 110 aroundthe pin 124 (in a clockwise direction as shown) and likewise results inthe same rotational movement of the second arm 114 (again, in theclockwise direction as shown). As a result of the rotational movement,the first end 122 of the throttle cable 120 is pulled as the acceleratorpedal 110 rotates about the pin 124. As shown in FIGS. 1 and 2, the fullextent of rotation of the pedal 110 is illustrated by the two positionsof the pedal.

The first end 122 of the throttle cable 120 travels along asubstantially linear path 140 as the pedal is actuated (FIG. 3). Thistravel is also represented in FIG. 1 by reference numeral 142 as astroke length or pull distance of the throttle cable 120. The throttlecable end 122 follows arc 144 (FIG. 3) controlled by the pin 124 orpedal pivot location. This has a minimal change to the pedal to cablestroke ratio. The line of action for the throttle cable 120 is alignedwith the top of the accelerator pedal 110, i.e., with the top of thesecond portion 114 of the accelerator pedal 110. Although there may be asmall variation in the ratio, the design intent with the currenttechnology is to maintain a linear accelerator pedal input. Thus, thecable pull ratio traditionally matches the top of the accelerator pedal110, and there is only a small incidental variation in the ratio, so thecable pull ratio is driven by the pedal ratio. This is represented by alinear plot 146 in FIG. 4.

Where the accelerator pedal 110, 1120 and the brake pedal 100 aredepressed at the same time, i.e. simultaneously, it is desirable thatthe vehicle not move. Therefore, it is desirable that the enginethrottle opening is slower than the brake application. It becomesnecessary to design the brake force to increase faster than the enginetorque when both brake and accelerator pedals are depressed at the sametime. This can be achieved with a variable ratio accelerator pedal, oneoutput of which is illustrated by plot 150 in the graphicalrepresentation of FIG. 4. As mentioned in the Background, it ispreferable to limit the complexity and number of changes to incorporatea variable ratio accelerator pedal. To that end, a new pedal assembly200, 1100 is shown in FIGS. 5-11 in order to achieve the variable ratio,preferably a first ratio 152 where there is an increased or greaterpedal stroke relative to cable stroke through an initial portion ofaccelerator pedal depression, and then a second ratio 154 shown in FIG.4 as having the same ratio as that of the prior art arrangement of FIGS.1-3. Of course the particularly selected ratio may vary withoutdeparting from the scope and intent of the present disclosure, althoughthese are preferred ratios.

Reference numerals in the “100 series” (such as pedal assembly 100 inFIGS. 1-3) now identify like components by reference numerals in the“200 series” (such as pedal assembly 200 in FIGS. 5-11), and newcomponents are also referenced by new numerals in the 200 series. Here,pedal assembly 200 is an accelerator pedal assembly which includes anaccelerator pedal 210 having a first arm or portion 212 (through which aforce is applied to the pedal) and a second arm or portion 214 thatconnects with an accelerator/throttle cable 220, particularly a firstend 222 thereof. The one-piece pedal 210 is mounted for rotation on pin224 that is secured to a mounting surface or mounting stay 230. Themounting stay 230 is secured to a firewall or panel (not shown) and thepin 224 allows pivotal movement of the pedal 210. Rotation of the firstarm 212 rotates the pedal 210 around the pin 224 (in a clockwisedirection as shown) and likewise results in the same rotational movementof the second arm 214 (again, in the clockwise direction as shown).

As a result of the rotational movement, the first end 222 of thethrottle cable 220 is pulled as the accelerator pedal 210 rotates aboutthe pin 224. The first end 222 of the throttle cable 220 travels along apath 240 (FIG. 6) when the accelerator pedal 210 is actuated and thispath is initially oriented at an angle “α” relative to the arc stroke ormovement 242 of the accelerator pedal. By way of example, angle α mayrange from approximately 45° (for instance as shown in FIG. 6) toapproximately −7°. At the end of the stroke, the throttle cable 220 isvirtually tangent (see reference numeral 260 in FIG. 6) to the arcstroke 242 of the accelerator pedal 210. Thus, the ratio of the pedalstroke to the cable stroke varies as illustrated in FIG. 4, from aninitial ratio 152 to a second ratio 154. Consequently, the cable pullratio 152 transitions to a second ratio 154 resulting from thepurposeful, initial positioning of the throttle cable 220 at an angle αto the arc path of the pedal 210 that then transitions to become tangentwith the arc path of the accelerator pedal.

In this manner, where the accelerator pedal 210, 1120 and the brakepedal 1110 are depressed at the same time, i.e. simultaneously, theengine throttle opening is initially and desirably slower than the brakeapplication. The new pedal assembly 200 effectively achieves the desiredvariable ratio by angling a surface 270 of the mounting stay that isoriented perpendicular to the initial path 240 defined by angle a. Ifthe angle a is changed, then likewise the angle of surface 270 isaltered to provide proper orientation of the throttle cable end 222 withaccelerator pedal 210.

Preferably the pedal 210 is a one-piece member without moving linkages.This eliminates undesired complexity, yet purposeful angling of thethrottle cable 220 at the attachment point 222 with the acceleratorpedal 210 still provides the desired variable ratio. This is alsoaccomplished in a manner that does not require undue alteration ofsurrounding components in an existing vehicle design.

This written description uses examples to describe the disclosure,including the best mode, and also to enable any person skilled in theart to make and use the disclosure. The patentable scope of thedisclosure is defined by the claims, and may include other examples thatoccur to those skilled in the art. Such other examples are intended tobe within the scope of the claims if they have structural elements thatdo not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal language of the claims. Moreover, this disclosure isintended to seek protection for a combination of components and/or stepsand a combination of claims as originally presented for examination, aswell as seek potential protection for other combinations of componentsand/or steps and combinations of claims during prosecution.

What is claimed is:
 1. A pedal assembly comprising: a mounting stay; apin fixedly secured to the mounting stay; a one-piece accelerator pedalwithout moving linkages mounted to the pin for rotational movement aboutthe pin relative to the mounting stay; and a throttle cable operativelyconnected to the accelerator pedal for movement thereby as theaccelerator pedal rotates, at least one of the accelerator pedal and themounting stay configured to provide a first ratio of pedal strokemovement relative to cable stroke movement at initial depression of theaccelerator pedal, and a different, second ratio of pedal strokemovement relative to cable stroke movement upon further depression ofthe accelerator pedal, wherein the throttle cable is secured to theaccelerator pedal for initial movement at an angle relative to a tangentof a pedal travel path, and the angle ranges from approximately 45° toapproximately −7° relative to the tangent of the pedal travel path. 2.The pedal assembly of claim 1 wherein the throttle cable is tangentialto the pedal travel path at the end of the cable stroke.
 3. The pedalassembly of claim 1 wherein the mounting stay includes a mounting regionthat receives the throttle cable and orients the throttle cablesubstantially perpendicular to an initial portion of the pedal travelpath.
 4. The pedal assembly of claim 1 wherein the accelerator pedalincludes a mounting region that receives a first end of the throttlecable.
 5. The pedal assembly of claim 1 further comprising a brake pedalassembly that is configured to provide a brake force that is greaterthan an engine torque.
 6. The pedal assembly of claim 5 wherein thebrake force is greater than the engine torque during the first ratio ofpedal stroke movement relative to cable stroke movement at initialdepression of the accelerator pedal.
 7. A pedal assembly comprising: amounting stay; a pin secured to the mounting stay; an accelerator pedalmounted to the pin for rotational movement about the pin relative to themounting stay; a throttle cable operatively connected to the acceleratorpedal for movement thereby as the accelerator pedal rotates, at leastone of the accelerator pedal and mounting stay configured to provide afirst ratio of the accelerator pedal stroke movement relative to cablestroke movement at initial depression of the accelerator pedal, and adifferent, second ratio of the accelerator pedal stroke movementrelative to cable stroke movement upon further depression of theaccelerator pedal; a mounting region on the mounting stay that receivesthe throttle cable and orients the throttle cable substantiallyperpendicular to an initial portion of an angled travel path of theaccelerator pedal; and a brake pedal assembly that is configured providea brake force that is greater than an engine torque; wherein the brakeforce is greater than the engine torque during the first ratio of pedalstroke movement relative to cable stroke movement at initial depressionof the accelerator pedal.
 8. The pedal assembly of claim 7, wherein thethrottle cable is secured to the accelerator pedal for initial movementat an angle relative to a tangent of the angled travel path.
 9. Thepedal assembly of claim 8 wherein the angle ranges from approximately45° to approximately −7° relative to the tangent of the angled travelpath.
 10. The pedal assembly of claim 7 wherein the throttle cable istangential to the pedal travel path at the end of the cable stroke. 11.A method of varying ratios of pedal stroke movement relative to cablestroke movement during actuation of an accelerator pedal comprising:mounting the accelerator pedal to a pin for rotational movement aboutthe pin; connecting a throttle cable to the accelerator pedal formovement in different first and second ratios of pedal stroke to cablestroke movement during actuation of the accelerator pedal; and providinga greater braking force than engine torque during the first ratio ofpedal stroke movement relative to cable stroke movement at initialdepression of the accelerator pedal.
 12. The method of claim 11 furtherincluding securing the throttle cable to the accelerator pedal forinitial movement at an angle relative to a tangent of a pedal travelpath.
 13. The method of claim 11 further including providing the firstratio of pedal stroke movement relative to cable stroke movement atinitial depression of the accelerator pedal, and the different, secondratio of pedal stroke movement relative to cable stroke movement uponfurther depression of the accelerator pedal.
 14. The method of claim 13further including providing a greater ratio of pedal stroke movementrelative to cable stroke movement during the initial depression of theaccelerator pedal than later in the pedal stroke movement between thefirst and second ratios.
 15. The method of claim 11 further includingforming the accelerator pedal as a one-piece component without movinglinkages.